混凝土抗氯离子渗透性PERMIT试验方法改进及工程应用

因抗渗性差导致有害物质侵入造成钢筋锈蚀从而使结构功能劣化是混凝土耐久性问题的主要成因.PERMIT离子迁移方法是目前唯一可用的商业化混凝土抗氯离子渗透性现场测试方法,但该方法目前尚存在一些亟待研究的问题.为了完善该方法,试验研究并理论解释了PERMIT离子迁移方法峰值电流与氯离子迁移系数的关系,并根据试验结果得到了PERMIT离子迁移方法与RCM快速氯离子迁移方法的关系.研究结果简化了测试和数据处理过程,并建立了PERMIT试验方法与我国现行标准的换算关系.作为工程应用,测试了哈大客运专线混凝土箱梁的抗氯离子渗透性,验证了改进方法的有效性.

Improvement and Application of PERMIT Ion Migration Method for Determining Permeability of Concrete

Corrosion of rebar due to invasion of harmful substances,especially chloride ions,is the major cause of performance degradation of concrete structures.PERMIT ion migration method is the only commercially available in-situ method worldwide for measuring chloride permeability in concrete.However,this method has some problems to be solved.In order to improve this method,the relationship between peak current and chloride migration coefficient obtained by PERMIT test was experimentally studied and theoretically explained,meanwhile,based on experimental results,the chloride migration coefficients determined by both Rapid Chloride Migration test(RCM for short)and PERMIT test were compared.Testing and data processing procedure can be simplified based on the research achievements and the relationship between PERMIT ion migration method and national standard method is established.As an engineering application,the chloride permeabilities of pre-stressed concrete box girders of Harbin-Dalian passenger line were evaluated to verify the effectiveness of the improved PERMIT method.